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By P. B. Baxendell

The performance of a water-drive reservoir having a gas cap depends primarily on the movement of the gar-oil and oil-water contacts. The movement of the contacts during production depends in turn on fluid withdrawals and how the reservoir pressure changes as fluids are produced from the reservoir; that is, on how effectively the aquifer maintains pressure by replacing withdrawals. inasmuch as pressure changes, fluid withdrawals, contact positions, and produced gas-oil and oil-water ratios are interdependent, the analysis and prediction of the performance of a reservoir produced in a given way must take into account this interdependence throughout depletion. This paper presents an analysis which, within the limitations of the assumptions made, yields an engineering approach to predicting future performance based on reservoir pressure and production history. The most significant assumption is the method of extrapolation of future gas-oil and water-oil ratios. The extrapolation procedure smoothly increases both ratios to preselected values as the remaining oil column undergoes a specified decrease in thickness. This preselection is made on the busis of previous field experience in depletion of similar reservoirs under similar conditions. For computing future performance a vdumebic balance L combined with the differential equation defining pressure distribution in the aquifer to obtain positions of water-oil and gas-oil contacts. From these positions are extrapolated produced water-oil and gas-oil ratios. Reservoir performance can be investigated when oil production rates are dependent upon various factors including the performance of the reservoir itself. Examples of practical application of the procedure are included. INTRODUCTION To predict performance of water-drive reservoirs with gas caps and thin oil columns, it is necessary to describe the motions of the fluids within the reservoir during the entire production period to depletion. These motions depend on the pressure changes and on the withdrawal of oil, gas and water. Production of oil from the oil zone primarily causes water to move in to take its place; production of gas from the cap tends to cause oil to migrate into its place. In addition, the volumes of oil and gas remaining in the reservoir depend on changes in the pressure, since a decrease in pressure causes fluid expansion, gas liberation and oil shrinkage. A method of relating the future pressure to total withdrawals is used to describe the motions of fluids within the reservoir under conditions arising in possible modes of production. The analysis is based on two relationships and will reduce the problem to one amenable to digital computation. The first of these concerns the dependence of the pressure distribution in the entire aquifer furnishing the water drive upon the total reservoir withdrawals. This dependence is dictated by the permeability distribution and the extent of the aquifer; at present, such information is most readily obtained from the performance history by means of the resistancecapacitance reservoir analyzer. The second relation involves withdrawals, pressure in the reservoir, and movement of oil, gas, and water within the reservoir. The analysis is subject to certain simplifying assumptions that are necessary to permit solution of the problem. A comparison of the methods of this paper with those presently practiced is pertinent. One method of analysis is to use the reservoir analyzer to predict reservoir behavior based on aquifer characteristics determined from production history. Inasmuch as the total withdrawal rate depends upon the gas-oil and water-oil ratios, which depend in turn upon, among other things, the positions of the gas-oil and water-oil contacts, these ratios must be assumed in advance. In this paper these ratios are, instead, related to the computed positions of gas-oil and water-oil contacts. Thus, our method can be applied to problems in which the oil production rate is limited by produced gas-oil ratio, or to problems in which it is desired to determine the variable gas injection rate that will maintain the gas-oil or water-oil contact stationary. These problems cannot be worked satisfactorily on the analyzer. Another method presently used is based on a paper by Hurst.' Since his procedure is dependent upon using the solution of the heat flow equation, which requires constant permeability within the aquifer, and our procedure recognizes variations of permeability in

By Alden B. Greninger

THE time-honored description of the growth of metal crystals to form polycrystalline aggregates is. one in which two important steps are considered: (1) nucleation, and (2) dendritic growth, each dendrite starting from its individual nucleus and resulting (upon slow cooling, assuming no solid phase changes) in a macrograin. This picture of the process of crystallization is incomplete, and it is with the hope of enlarging upon it that the following summary and correlation of experimental results are given. MOSAIC STRUCTURE For an exact definition of the mosaic structure of metal crystals-if, indeed, one can be found that will hold for all metals-one must await the results of much experimental work in this field. The writer's investigations have been. confined almost entirely to copper and a few of its alloys. The following terms are proposed, and will be used in this report: Macromosaic Structure1.-Large-scale mosaic structure; more specifically, mosaic structure of a scale large enough to produce splitting of Laue spots on back-reflection Lane X-ray patterns2. The deviation from exact parallelism of neighboring macromosaics varies from a few

Jan 1, 1935

By C. F. Cornell, Henderson, A. F. Dunyon, D. A. Dahlstrom

IN processing magnetic taconites several steps of crushing, grinding, classification, and magnetic separation are required to produce a 60+ pct Fe concentrate. Usually the final concentrate is in a slurry form of 55 to 70 pct solids by weight and is further characterized by a particle size of 60+ pct -325 mesh. In taconite plants already completed or under construction the conventional method used to obtain pellets suitable for blast furnaces is to filter the concentrate slurry, ball the filter cake, and then harden the green pellets in a traveling grate or in a vertical shaft furnace. Large tonnages must be handled in minimum floor space, with reduced maintenance and lowest possible operating cost. Filtration must therefore achieve two objectives: 1) high filtration rate-in terms of pounds of dry solids per hour per square foot of filtration area-at a low filtrate solids concentration, and 2) a filter cake moisture that will always permit efficient balling within the normal fluctuations of plant operating conditions. If moisture contents are too high, balling may be impossible or result in a mushy ball without enough green strength for the firing operation.

Jan 3, 1957

By James J. Norton, Lincoln R. Page

Effective methods for determining grade and reserves of pegmatites in advance of mining have been developed in recent years. When intensive work began on the economic geology of pegmatites during the early years of World War II, it was widely believed that grade and reserves could be estimated only in a most general way. The literature indicated that not all pegmatite deposits are unpredictable, but statements emphasizing unpredictability and irregularity seem to have been more widely accepted. Many standard references reflect the prevailing opinion that minerals are unsystematic in their occurrence in pegmatites. Pegmatites have been de- scribed as "notorious for their irregular structure," and minerals within pegmatites as "irregularly distributed," "irregularly disseminated,'' of "erratic occurrence," "proverbially erratic in distribution," "characterized by extreme irregularity in size and distribution of the essential minerals, and variety and proportion of the accessory minerals, and "spotty."

Apr 1, 1956

By R. O. Scattergood, P. Beardmore, M. B. Bever

THE stored energy and microhardness of a Au-Ag alloy deformed by explosive loading were measured previously as functions of shock pressure' and compared with corresponding data for drawn wires.' The difference of the two processes has been explored further by investigating the annealing behavior of explosively loaded specimens and drawn wires. Sheet specimens, 0.042 in. thick, of a Au-Ag alloy containing 82.6 wt pct Au were explosively loaded in stacks of four.3 Wires prepared from the same melt of alloy were drawn through dies.' The annealing kinetics were determined by microhardness measurements on separate specimens for each annealing temperature and time. Several values of the stored energy were measured by tin-solution calorimetry Experimental details are given elsewhere. Wires were drawn until the microhardness or stored energy equalled the corresponding values of the explosively loaded specimens as nearly as possible. Wire drawn to a true strain 7 of 0.09 had approximately the same hardness and stored energy as specimens explosively loaded to a shock pressure of 70 kbar. The microhardness of specimens

Jan 1, 1963

By J. H. Dewey, J. McCreedy

Ontario Division of The International Nickel Company of Canada, Limited, operates five under- ground mines and one open pit on the rim of the Sudbury basin. In 1962, the total underground ore production was over 10 million tons which was mined mainly by blasthole and caving methods with the remainder by cut-and-fill, square set and undercut-and-fill techniques. Because of the large expenditures required annually for explosives, a great deal of study has been devoted toward cost reduction in this field. The large saving effected by ammonium nitrate-fuel oil combination at the open pits, along with reports of its success in underground mining in Sweden, generated much interest in the possibility of its use as a replacement for high explosives in the underground operations at Inco. In June, 1960, a research engineer was assigned to this project, and preliminary investigations soon indicated substantial savings and important safety advantages. The final results of the program were successful beyond any expectations and ANFO is now used exclusively in all Inco mining operations in Ontario except shaft sinking.

Jan 11, 1964

By Thomas Egleston

The copper-bearing rocks of Lake Superior are composed of a series of metamorphic rocks, comprised under the names of amygdaloid and conglomerate, in which the copper and silver found with them are pseudomorphs. These rocks, generally, have Well-defined walls which cause them to separate easily. Generally, the country rock is sterile, but it occasionally rises into the copper-bearing rock, and then carries copper. Usually, the amygdaloids carry copper, and the greenstones or melaphyres which encase them do not. There is a very generally received opinion that the copper in these beds occurs in shoots. This does not appear to be proved, though the opinion seems to have some foundation from the experience of the Calumet & Heela Mine, where a body of poor rock has been left, which, on the mine map, shows a general direction. The theory may be true of that individual mine, but too little work has been done in the other mines to draw any decided conclusion. The copper is very unequally disseminated in the rock, if any given piece be taken as an example, but, if the whole copper-bearing series be considered, its distribution is uniform. It may prove that there are certain directions in which the copper has been deposited more abundantly than in others, and these may be found to correspond with certain geological causes, but up to the present time the knowledge gained is not sufficient to warrant any general conclusion. These rocks are supplemented by a series of true fissure veins, of which there are several systems, making the amount of native copper very large. Unfortunately, except in the fissure veins, known as " mass-mines," the copper is so scattered through the rock, and is in such a fine state of division, that, although it is not always difficult to mine, it is always difficult to dress it sufficiently to make it pay. The metal is so unifornily distributed throngh these copper-bearing rocks that detached pieces, called " float," are found in digging on almost any land in the country. These pieces vary from very small fragments, weighing not more than a few ounces, up to many pounds. In one instance, in making an excavation for a cellar of a

Jan 1, 1879

By E. H. Rennhack, J. F. Libsch

Definite transition behavior was found in unalloyed titanium at 0.13 pct 0 equivalent. The addition of 0.5 Sn, 1.0 Al, 0.5 Al, and 1.0 Sn lowers the tvansition temperature of titanium at oxygen equivalents exceeding 0.22, 0.29, 0.40, and 0.51, respectively. Metallographic evidence indicates that progressive amounts of oxygen restrict deformation at low temperatures resulting eventually in brittle fracture. The presence of tin or aluminum is thought to alter the atomic distribution of oxygen within the titanium lattice in such a manner as to facilitate some degree of slip and twinning. 1 ITANIUM-like iron and zinc experiences a transition from ductile to brittle fracture with decreasing temperature. The presence of sufficient quantities of the interstitial elements, carbon, oxygen, and nitrogen in solid solution, has been shown to progressively lower the room-temperature impact resistance of titanium with increasing interstitial content.1"1 Ogden,et al,2 reported finding no transition from ductile to brittle fracture with decreasing temperature in iodide titanium. However, a definite transition was found to occur at 0.36 pct 0 equivalent in an alloy containing 0.47 pct carbon in solid solution. The oxygen equivalent in this case was obtained by assuming the effects of carbon, oxygen, and nitrogen in combination on the impact properties of titanium to be additive on the same basis as their separate effects on tensile strength, namely: Oe = 2/3 (pct C) + pet 0 + 2 (pet N) They concluded that the tendency toward transition behavior is dependent on the total interstitial content in solid solution and not on any one particular interstitial element. Rennhack,4 however, recently found transition behavior in iodide titanium at an oxygen equivalent of 0.17 pct. Ogden, etal3, reported that the strengthening effects of carbon, oxygen, and nitrogen in titanium decrease with the addition of tin. They showed that tin additions increase the tolerance of titanium for the interstitials, that is, 10 pct Sn permitted individual additions of up to 0.4 wt pct of the interstitial elements without any significant loss in ductility. Aluminum tends to decrease ductility and impact strength of titanium for a given interstitial ~ontent.3 Van Thyne and Kessler5 found that the solid solubility of carbon in titanium doubled in the presence of 10 pct Al. The precise effects of tin and aluminum in the nrespncp of rorvfen nn the impact properties of titanium had previously not been determined. The high oxygen tolerance of titanium containing tin may provide a suitable means for improving the impact properties of titanium containing the interstitial elements, particularly oxygen. Unlike tin, however, aluminum has a high affinity for oxygen and will reduce rutile titanium dioxide (TiO2)by a thermit-type reaction.6 Thus, the atomic distribution of oxygen in titanium might be different in the presence of aluminum. The present work was undertaken to: 1) Determine the effect of oxygen on the transition behavior of unalloyed iodide titanium. 2) Determine the effect of small amounts of tin and aluminum on the transition behavior of iodide titanium in the presence of oxygen and other interstitial~. EXPERIMENTAL Three different lots of iodide titanium were employed to prepare the alloys studied in the present work. Their chemical composition is presented in Table I. The compositions of the tin and aluminum used for alloying are shown in Table 11. Oxygen additions were made using calcined rutile titanium dioxide (TiO2)of 99.7 pct purity. Alloy Preparation—Four titanium-base alloys containing separate additions of 0.5 and 1.0 pct each

Jan 1, 1960

By Evan Just

THE high standards of living and improved national security that industrialization can bring are so evident that no country can be named that does not cherish the hope of industrializing. With such a universal aim, why do many countries unable to develop their own industries accomplish so little toward attracting the foreign private investor, who alone can provide them with the necessary capital and skill? Obviously, because they fail to under- stand what constitutes a favorable climate for investment, because they have false notions about being exploited or dominated by the foreign investor, or because they are so nationalistic they refuse to permit outside assistance. The purpose of this paper is to aid the citizens and policy makers of developing countries in achieving their aims, by defining the conditions which en- courage investment and portraying the results of a policy of encouragement. The following is quoted from Eugene R. Black, president of the World Bank:

Jan 6, 1957

THE refining period of an open-hearth heat blends imperceptibly into the finishing period, during which final adjustments are made in slag composition, in bath action and temperature, and in composition of the steel, in order to prepare it for casting into ingots. Operations must be governed by the consideration that alterations in the character of the heat during the finishing period must be held to a minimum. In a broad sense, the finishing and deoxidation period of a heat may be said to begin when the action of the last ore addition has ceased, and to end when the teeming of the ingots is completed. INGOT STRUCTURES A survey of the relative advantages and disadvantages of different types of ingot structure is required because deoxidation treatments during the finishing period control the amount of gas evolved during solidification and consequently determine the type of ingot structure. Four classes of ingots are recognized, depending upon the degree of deoxidation to which the steel has been subjected. These types are killed, semikilled, capped, and rimmed; typical examples of their structures are represented by ingots 1, 2, 5, and 7, respectively, of Fig 9-1. The actual ingots from which these cross sections were sketched were all poured to the same height (indicated by the dotted lines) in the same type and size of bottle-top molds. The eight drawings of the figure represent selected types of ingot structure in a continuous series from "dead killed" to "wild," resulting from variations in the total quantity of gas evolved, from none at all to copious amounts, during solidification of the steel in the mold. Killed and semikilled steels are adjacent at the "quiescent" end of the ingot structure series where only small amounts of gas are evolved. The term "quiescent" describes the action of the molten metal during and subsequent to the teeming of killed and semikilled steels. Capped and rimmed steels are adjacent at the

Jan 1, 1951

In introducing last year's Industrial Minerals Review, Stan Lefond accurately predicted that the 1974- 75 period would be quite difficult and frustrating. Although 1974 demand and prices for most industrial minerals were exceptionally strong, operating costs also rose rapidly-while shortages of supplies and equipment, symptomatic of an overheated economy, occurred from coast to coast. Thus, at the end of 1974 recessionary forces were accelerating-and the minerals industry will soon be facing falling demand as a consequence of sharp declines in auto production, housing, appliances, and other consumer goods. Moreover, when sales weaken, the high-volume, low-prices industrial minerals will incur sharply increased unit costs. To maintain adequate profit margins under these conditions will require cautious and perceptive management.

Jan 2, 1975

By John D. Wiebmer

Lignite Development in North Dakota is a "shotgun wedding" according to former state senator Robert L. Stroup-the unwilling groom (North Dakota) is being led to the altar by the nation's demand for increased coal production. The state's attorney general, Allen I. Olson, reacts to the situation this way: "We have no specific coal policy. We plan to keep the whole matter down to a dull roar and drag our feet until we see how we fit into the national energy picture." But despite a state administration labeled as "cautiously negative" toward resource development, North Dakota has experienced a twofold increase in annual lignite production within the last two years. And within the next four years, three more mine additions will double the state's output again.

Jan 8, 1977

By V. R. Garfias, R. V. Whetsel, J. W. Ristori

Preliminary estimates indicate that world consumption of petroleum and related fuels in 1938 will be close to 1,908,000,000 bbl., or approximately 7,000,000 bbl. less than in 1937. This total does not include military consumption in foreign countries, which for obvious reasons is not made public. Foreign military consumption in any one year, however, is approximately represented by the difference between the total production of petroleum and related fuels and the "partial total" consumption above noted, after adding any decrease, or subtracting any increase in stocks in the United States. Fig. 1 illustrates this "difference" and shows that in 1937 and 1938, owing to the wars in China and Spain and the possibility of armed conflict in Central Europe, foreign military consumption—and possibly additions to foreign stocks—increased nearly 70,000,000 bbl. in 1937 over 1936 and remained at this high rate throughout 1938. No official information on foreign oil stocks is available to the writers. Table 1, recently published, purports to give the oil in storage in some of the European countries, but it is not known whether the figures include oil stocks for military purposes. It should be noted that with the annexation by Germany of Austria and part of Czechoslovakia the consumption of the country has increased to 53,000,000 bbl., which is about 36,000,000 short of the German produc-

Jan 1, 1939

By J. W. Ristori, R. V. Whetsel, V. R. Garfias

Preliminary estimates indicate that world consumption of petroleum and related fuels in 1938 will be close to 1,908,000,000 bbl., or approximately 7,000,000 bbl. less than in 1937. This total does not include military consumption in foreign countries, which for obvious reasons is not made public. Foreign military consumption in any one year, however, is approximately represented by the difference between the total production of petroleum and related fuels and the "partial total" consumption above noted, after adding any decrease, or subtracting any increase in stocks in the United States. Fig. 1 illustrates this "difference" and shows that in 1937 and 1938, owing to the wars in China and Spain and the possibility of armed conflict in Central Europe, foreign military consumption—and possibly additions to foreign stocks—increased nearly 70,000,000 bbl. in 1937 over 1936 and remained at this high rate throughout 1938. No official information on foreign oil stocks is available to the writers. Table 1, recently published, purports to give the oil in storage in some of the European countries, but it is not known whether the figures include oil stocks for military purposes. It should be noted that with the annexation by Germany of Austria and part of Czechoslovakia the consumption of the country has increased to 53,000,000 bbl., which is about 36,000,000 short of the German produc-

Jan 1, 1939

Professor Somasundaran has given an excellent presentation of the numerous problems which remain to be solved before the selective aggregation of fine particulates is likely to see broad commercial application in the beneficiation of mineral fines. However it is useful, I think, to reiterate some of the major problem areas. The over-riding factor which has limited the development of selective aggregation techniques is that processes such as coagulation and flocculation tend to be inherently non-selective. Conditions which favor the aggregation of one kind of fine particles usually favor the aggregation of all kinds of particles. As Professor Somasundaran has pointed out, the state of aggregation of a fine-particle dispersion is primarily determined by the forces of interaction between the individual particles. In most systems, the dominant forces are: 1. van der Waals - London Dispersion forces between the particles themselves 2. electrical double layer forces 3. steric forces between adsorbed layers on the surfaces of the particles. The London Dispersion forces between like particles are always attractive, but for dissimilar particles dispersed in a fluid medium can, in some cases, lead to a net repulsion. Electrical double layer forces always lead to repulsion between like particles but can, again, cause either attraction or repulsion for dissimilar materials. The steric forces, which are by far the least understood of the three types, can also lead to attraction or repulsion depending on condi-

Jan 1, 1979

By G. Cartaud, F. Osmond

We have already devoted two previous memoirs to this question. In the firstL we collated and discussed the existing literature on the subject; in the second: we described the crystalline forms obtained by the reduction, at different temperatures, of ferrous chloride by hydrogen or by zinc-vapor. The conclusion from these researches was that the three allo-tropic states of iron—a, stable below A2; , stable between A2 and A3; and , stable above A3—all crystallize in the cubic system. The differences observed were such as are customarily encountered in the crystallographic records of many minerals of which allotropic varieties or isomerides are not known, and did not conform to the ordinary definition of polymorphism. It is, however, improbable that allotropic transformations, which are placed beyond doubt by a series of positive facts, do not involve some changes in the intimate structure. As a matter of fact, the crystals we did obtain were too small to allow of a precise examination, and this might introduce an element of uncertainty in the firm establishment of our conclusions. Professor H. Le Chatelier mas even led to think from some of our results that r-iron could very well be a rhom-bohedron simulating a cube, and not a true cube, and it will be remembered that the crystalline form of bismuth was for a long time incorrectly regarded as cubic. Allotropy does not, however, necessarily involve such a deduction. Without departing from the cubic system at all, a whole

Jan 1, 1907

By Felicia F. Peng

The computer graphic routines and digital simulation program of coal cleaning circuits have been developed in the Mineral Processing Engineering Department, West Virginia University. The functions of the program include computing, tabulation and graphing of 1) washability characteristics of raw coals, 2) blending, 3) Tromp distribution curves for two washer types-- water only and dense medium, 4) predicting the functional relationship of yield and qualities of clean coal product in individual and overall coal cleaning circuits in coal preparation plant, and 5) determining the optimal clean coal yield based on the market and environmental specifications. Amdahl 470 V/7A digital computer, Tektronic 4025 graphic terminal and Tektronix 4663 digital plotter with Fortran IV are used to achieve the goals. The simulation with the aid of graphic routine program of coal cleaning circuits is a useful tool for coal preparation engineers in evaluating the feasibility of proposed flowsheets, in investigating the effect of a modification in a unit operation of an existing plant, in analyzing the off-line optimization, and in comparing the alternative circuit control strategies. The coal cleaning process simulation with graphic routine can contribute greatly to the decision making processes of preparation plant design.

Jan 1, 1983

By J. J. K. Daemen, C. Fairhurst

Introduction The stress field around a supported tunnel can be considered as being composed of: i) the virgin (pre-mining) stress in the rock ii) the (elastic) change in this stress field caused by creating the opening iii) the (time-dependent ) change in the stress field produced by (i) and (ii) as a section of the rock breaks up iv) the (time-dependent) influence of the stress build-up in the support. Several authors have examined the conditions necessary to produce static equilibrium between the support, the rock, and the regional (in-situ) stress field. The analysis used by Labasse (1) is typical. Consider a circular tunnel radius R in a hydrostatic stress field (P), and a radial pressure pi exerted by the support. According to Labasse, the radius ‘b’ to which the rock will break* for a given support pressure, pi, can be calculated from: - the equilibrium equation: [ ] As a zone of broken rock develops around the opening, the stress circle for a point on the elastic-broken rock boundary moves to the right in the Mohr diagram until the radial stress in the broken zone s equal to the radial stress in the elastic zone.

Jan 1, 1971

Within the last century, and largely during the latter half of it, the increase of our knowledge of the development of man, both in his search for a livelihood and for power, and in the growth of his reason and conscience, has been greater than all we had known before. The great interest in all kinds of archaeological work and the many excavations made of buried and long forgotten places has put at our disposal historical records-not available, and in many cases not known before, and a study of these and other records of human progress from paleontological and geological sources has given us a much broader view of what we call "civilization" than was possible even a short time ago. The old idea that men were created with fully developed minds, speech and reason has yielded to the view that in the upward progress of the human race the development of the mind and reason has been a comparatively recent occurrence, as we think of the half million, and probably more, years that have passed since our earliest records of man were made. The traits that come to us without effort

Jan 1, 1939

By Edgar G. Hill

MUCH has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the [ ] united States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering view-point, pointing out the effect of the volumes transported, and the load factor at which they are operated, on the unit costs of transportation, as well as the effects on costs of the character of the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the [ ] refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. BASIC FORMULA FOR FLOW OF CRUDE OIL The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942